How to maximize the life of electric spindle bearings
7/10/2017 4:20:59 PM
      Theoretically, the service life of rolling bearings in centrifugal pumps in electric spindle bearings is 20,000 to 80,000 hours. However, the actual life depends on many factors - premature bearing failures can lead to costly equipment downtime, and sometimes even More serious consequences.
 
      Satisfactory spindle bearing life begins with the right choice. From the outset, spindle bearing designers have extended bearing life and equipment performance by choosing the right bearings for different applications. This process takes into account many factors such as load, hardness, bearing life prediction, operating environment, and so on.
 
Correct storage of Enske bearings
 
       In principle, all spindle bearings should be stored in their original packaging before installation. They need to be left in a clean, moisture-free, relatively constant temperature environment. Rolling bearings should be kept away from dust, water and corrosive chemicals. Shaking and vibration can permanently damage the mechanical properties of the bearing, so vibration must be avoided during handling and storage.
 
       Basically, all bearings must be stored horizontally, as some heavier bearings may be deformed by their own weight after standing for a long time.
 
       Pre-coated greased (or sealed) spindle bearings require special care because the density of the grease changes after prolonged storage. Thus, when the bearing is used for the first time, there will be a certain degree of rotational noise. Therefore, the shelf life of such bearings should be controlled on a first-in, first-out basis.
 
Spindle bearing cleaning
 
      Cleaning is very important for rolling bearings in spindle bearings. The surface roughness of the rotating surface of the bearing ring and the rolling elements is typically 1/10 μm. Such a smooth surface is very sensitive to damage caused by contaminants. The lubricating layer between the rotating faces is usually 0.2 to 1 μm. Particle-shaped impurities larger than the particle size of the lubricant may be excessively crushed by the rolling elements to cause partial pressure in the bearing steel, which may eventually cause permanent material fatigue. In addition to this, dust particles in the external environment can be up to 10 μm in size, which can also cause damage to the bearings. Therefore, a clean, dust-free environment is critical to the storage and installation of the bearings.
 
Ready to install again
 
       Spindle bearings should be carefully installed and removed using suitable tools. Industry experts estimate that 16% of premature bearing failures are due to incorrect installation. For large installations (for example in production plants), conditional installations are usually strictly controlled and suitable bearing mounting equipment can be used.
 
       However, in maintenance or replacement work, the environment is diverse. Therefore, in order to ensure the longest bearing life, comprehensive preparation is necessary for bearing installation.
 
       First of all, relevant documents, such as drawings, maintenance manuals, product manuals, etc., need to be carefully studied. Next, all bearing components, such as shafts, spacers, covers, gaskets, etc., must be kept absolutely clean and free from contamination. The status of adjacent components should also be checked carefully.
 
Careful installation and removal
 
       Depending on the application and the size and type of spindle bearings, choose the appropriate mounting method (mechanical or hydraulic) and tools. Here are some basic principles of bearing installation:
 
      1. Do not apply a mounting force on the rolling elements, which can easily lead to partial overloading of the rolling element and the contact surface of the race, resulting in premature failure of the bearing.
 
      2. Do not hit any hard tools (such as hammers, screwdrivers, etc.) directly on the bearing surface, which can cause the bearing ring to break or chip.
 
      3. Follow the instructions of the highly recommended installation equipment supplier.
 
      Approximately 90% of the rolling bearings have never been removed from their equipment, and usually only larger bearings are removed due to scheduled preventive maintenance procedures. As with the installation of a bearing, the bearing must be carefully prepared. During the disassembly process, ensure that adjacent components such as the shaft and bushing are not damaged. Choose the right method and tool for the bearing type, size and application.
 
      Designers should note that a well-designed bearing position can greatly simplify bearing installation and disassembly, thus reducing maintenance costs.
 
Correct lubrication of the spindle bearings
 
      Lubricants can isolate metal bearing surfaces (such as rolling elements, bearing rings, and bearing cages), thereby reducing friction, protecting metal parts, and preventing contamination and impurities. A wide variety of lubricants (including greases, oils and solids) are available for different operating conditions. Proper use of lubricants is important to extend the life of bearings and equipment.
 
      Bearing lubricants are subject to prolonged mechanical stress due to excessive rolling of the spindle bearing rolling elements, and the chemical properties of the lubricant may change over time, especially in high temperature, wet or contaminated environments. All of this leads to a gradual decline in the quality of the lubrication. Therefore, to ensure the longest service life, the bearings should be relubricated regularly. The lubrication cycle depends on operating conditions such as temperature, speed, environment, and so on. Only in pre-lubricated or sealed bearings (also known as "lifetime lubrication" bearings), bearing life is dependent on lubricant life.
 
      Lubricants must be properly stored in accordance with the manufacturer's instructions, with special care to keep the lubricant clean and free from contamination. Carefully check the quality of the lubricant before each use. Using an old or contaminated lubricant may cause the bearing to fail prematurely.
 
Condition monitoring and maintenance of spindle bearings
 
      In general, rolling bearings for spindle bearings are very reliable, although their life is limited. As with all other important components in the machine, they should be regularly inspected and maintained. The frequency of inspection and maintenance depends on the importance of individual applications and the operating conditions of individual equipment.
 
      Due to the critical role of the bearing, it is recommended to add a condition monitoring function during its design phase. Important parameters of the machine's operation, such as vibration and noise, can be continuously monitored to prevent precautions before unpredictable and costly equipment downtime.
 
Training - the foundation of good practice
 
      Practice makes perfect, but proper training is the foundation of practice. Well-known bearing manufacturers offer a variety of training courses for business, technical or workshop employees. If the technician has basic knowledge in handling the bearing, then major errors can be avoided. Design and product development engineers can maximize equipment performance and minimize life cycle costs by optimizing bearing design.